Not a whole lot - I use Waterfox, which is the 64-bit build of Firefox compiled with SSE, SSE2, etc plus the x64 instructions.

To this, I add NoScript and (sometimes, though not installed at present) Cookie Monster. I also have the switch to tab blacklist installed to kludge-out the tendency of Firefox to switch to a tab when you enter a URL that's already open.

Since my firefox is usually always maximized (where it is more compact), the non-maximized state doesn't really matter to me. Plus, I like having a place to click to drag my window around in case it is non-maximized.

Besides, it doesn't work properly due to the longer "Waterfox" title. The tabs overlap the button.

My interface has been updated.
No more back/forward buttons!
Just kidding, they're actually still there but are now hidden in the collapsible/show-upon-hover vertical toolbar on the left hand side. I only really use them if I have a need to access the right click menu and go back/forward more than a couple of pages. Otherwise I usually just right click anywhere and then select back or forward. Note how many buttons I've crammed onto the vertical toolbar, including my own bookmarks toolbar. On my laptop, which has the same interface but a smaller screen, many of those icons are hidden in the bottom add-on bar instead - compact and hidden again, and accessible by pressing CTRL + Q.

The full screen browsing experience is amazing. Here it is tab bar only:
And here it is with address bar/search bar (shown after pressing the "CTRL" key):

My Waterfox 7 RAM usage is hovering at around 800MB with these ~13 tabs open.

Next step: Eliminate the searchbar
(Well, anyone could do this actually through unifying the two into an omnibar, however the way I have my search bar configured (i.e. quick search bar, multiple icons for various search engines - click to search that engine, it's a Firefox addon) I couldn't just merge the two without severe impact to my daily browsing habits. I'm hoping to see if there's an addon that actually hides the searchbar until you press a button to expand/show it (that is compatible with the "quick search bar" addon I use), and I'll put it up on the same row as the tab bar if I find one.Edited by xd_1771 - 9/26/11 at 7:01pm

My interface has been updated.
No more back/forward buttons!
Just kidding, they're actually still there but are now hidden in the collapsible/show-upon-hover vertical toolbar on the left hand side. I only really use them if I have a need to access the right click menu and go back/forward more than a couple of pages. Otherwise I usually just right click anywhere and then select back or forward. Note how many buttons I've crammed onto the vertical toolbar, including my own bookmarks toolbar. On my laptop, which has the same interface but a smaller screen, many of those icons are hidden in the bottom add-on bar instead - compact and hidden again, and accessible by pressing CTRL + Q.
The full screen browsing experience is amazing. Here it is tab bar only:
And here it is with address bar/search bar (shown after pressing the "CTRL" key):
My Waterfox 7 RAM usage is hovering at around 800MB with these ~13 tabs open.
Next step: Eliminate the searchbar
(Well, anyone could do this actually through unifying the two into an omnibar, however the way I have my search bar configured (i.e. quick search bar, multiple icons for various search engines - click to search that engine, it's a Firefox addon) I couldn't just merge the two without severe impact to my daily browsing habits. I'm hoping to see if there's an addon that actually hides the searchbar until you press a button to expand/show it (that is compatible with the "quick search bar" addon I use), and I'll put it up on the same row as the tab bar if I find one.

How did you make the minimize, maximize, and close buttons like that in first screenshot?

^ That came with the Firefox theme "MX-3", althouhg I don't use it anymore. My current UI has changed and is a transformation of the default Firefox UI. It's much more compact and IMO better. I will upload a screenshot sometime!

^ That came with the Firefox theme "MX-3", althouhg I don't use it anymore. My current UI has changed and is a transformation of the default Firefox UI. It's much more compact and IMO better. I will upload a screenshot sometime!

Thanks for the quick response xd_1771 and here is my browser customization

Perhaps I might inspire you all in the process this time around with the newest revision of my web browsing setup.

First of all, I have completely eliminated every interface............

Just kidding well, both that and not kidding. Pressing CTRL key (addon MinUI) reveals my integrated single toolbar which includes the addressbar, search bar, and two other buttons:

The two buttons on top reveal my vertical toolbar and tab bar (both are also accessible by quick keyboard shorcut):
That's right, I went vertical tab side bar. The big premise for this vertical tab bar though is that it is integrated directly with the Firefox Tab Panorama/Grouping feature - but it's better in some ways. No visual organizer, but you do have the ability to more quickly select and move several tabs between groups :)
I still use the regular visual organizer (which I access by keyboard shortcut) in a way similar to Windows Flip 3D.

All my functionality is on the left-bound addon bar (Vertical Toolbar). From here is a command center that allows me to flip back and forth between pages (although mouse gesture and right click -> back has largely replaced that), access page in another browser, open search, bookmarks, history, downloads or addon sidebars (I use sidebars for everything now - even web searches i.e. Google, via addon Briteclick) - access customization settings for Stylish and Greasemonkey, Print functionality, quick e-mail access (Webmal notifier), Sync, Zoom controls and amount, and a Japanese-English dictionary/translation tool (Moji) located in a sidebar.

The rather big thing about this minimalization of all browser interfaces unless necessary though is the opportunities it provides for actually browsing the web.

Tile Tabs addon allows me to split up my tab to include more than one webpage in several different ways. Here I am browsing an OCN page while making a Newegg combo deal search to recommend an APU combo. So if anyone was ever wondering, this is how I get those ridiculous part recommendations done so fast!!!!

I can do more than just vertical split by the way. Here is a triple split with the OCN thread, a Newegg combo search page and an actual Newegg combo page. You will notice that both the right tabs are zoomed out (ctrl + scroll wheel) so I can actually see stuff on the page:

And this is all just on one of my glorious two 1920x1080p 24" monitors When I have browsers running on both monitors (rarely, I'm either watching media on the other monitor or doing something else on it)

What I love most about this single and simplified interface is that it can work with all needs, all PCs and screens of all sizes (even touch screen tablets due to the positioning of the buttons and auto-hide features) - particularly helpful when I use portable Firefox, then I don't have to adjust to using a modified profile that may work better on a smaller screen. While my interface customizations seem small-screen/touch-screen optimized, the benefit on desktops is the ability to control most everything by keyboard shortcut.

VT throws the tab bar down the left of the screen, so I can see 45 tabs at a time, and their full titles, and I still get a full-height browser window for the web page I'm using.

TGM is a genuis idea, lets me create a toolbar with one tab per project or category of tabs I'm working on, and switch between them, suspend or hibernate the ones I'm not using, full drag/drop, session backup, etc etc. (Check that "browser.sessionstore.restore_hidden_tabs" is TRUE if using TGM; tabs can unexpectedly be lost or go blank if hidden tabs are not restored!)

Apart from that I don't use a lot. FlashBlock (don't run flash unless clicked), OptimizeGoogle (fix google links so copy/paste works), FireGestures (mouse gestures), Status4Evar (status bar). Those are the main ones.....